Audio systems sometimes include one or more acoustic transducers to convert acoustic signals into electrical signals (e.g., microphones) to detect acoustics in the environment in which they operate, and sometimes also include acoustic drivers (e.g., loudspeakers) to reproduce acoustic audio content from an electrical signal. Microphones may be deployed in such systems for the purpose of detecting desired audio, which may include a user's speech for applications such as automatic speech recognition, virtual personal assistants, and communications (e.g., telephone), for example. Often, the environment in which the audio system is used includes additional acoustic sources other than the desired audio, such as televisions, other audio systems, noise from equipment, etc., and these alternate acoustic sources may sometimes interfere with the detection and/or processing of the desired audio, e.g., the user's speech. The acoustic environment in which the audio system operates may generally be unknown, and may change significantly over time. Accordingly, alternate or undesired acoustic signals may be unknown at the outset and may also change significantly over time.